To find the diver's elevation when he is 2/3 of the way down, we need to calculate 2/3 of 97.2 feet.
2/3 * 97.2 = 64.8 feet
Therefore, the diver's elevation when he is 2/3 of the way down is -64.8 ft or negative 64 point 8 ft. The correct answer is -64.8 ft.